Everex Micro Enhancer.


 Ev236  UltraGraphics   (Trident chip).
 Ev620  Vision VGA      (Trident chip).
 Ev629  Viewpoint TC    (Tseng 4000 chip with special DAC 16M colors).
 Ev673  EVGA            (Trident chip).
 Ev678  Viewpoint       (Trident chip).


 3C2h (W)): Misc Output Register
   bit 5  Bit 1 of Bank No.
 Note: this register can be read from port 3CCh.


 3C4h index  8  (R/W):
   bit 7  Bit 0 of Bank no.


 Bank switching.

 Everex uses a two bit bank no. with bit 0 in 3C4h index 8 bit 7
 and bit 1 in 3C2h bit 5.



 ID Everex Micro Enhancer:

 RP.BX:=0;
 vio($7000):
 IF RP.AL=$70 THEN
 BEGIN
   NR:=RP.DX SHR 4;
   case NR of
     $236,$620,$673,$678:TRIDENT;
     $629:Tseng_4000;
   else EVEREX Ev(Nr)
   end;
 END;


 BIOS extensions:

----------100070-----------------------------
INT 10 - VIDEO - Everex Micro Enhancer EGA/Viewpoint VGA - EXTENDED MODE SET
       AX = 0070h
       BL = mode (see below)
SeeAlso: AH=00h,AX=6F05h,AX=7000h/BX=0004h,AH=FFh"GO32"

Values for video mode:
    text/ text   pixel pixel    colors disp scrn monitor  adapter
    grph  resol  box   resoltn         page addr
00h = G                640x480   16              multsync EGA,VGA
01h = G                752x410   16              multsync EGA,VGA
02h = G                800x600   16              multsync EGA,VGA
03h = T   80x34                                  multsync EGA,VGA
04h = T   80x60                                  multsync EGA,VGA
05h = T   94x29                                  multsync EGA only
06h = T   94x51                                  multsync EGA only
07h = T  100x43  8x14            16                       VGA only
08h = T  100x75  8x8             16                       VGA only
09h = T   80x44                                  EGA      EGA only
0Ah = T  132x25                                  EGA      EGA,VGA
0Bh = T  132x44                                  EGA      EGA,VGA
0Ch = T  132x25                                  CGA      EGA only
0Dh = T   80x44                                  mono     EGA only
0Eh = T  132x25                                  mono
0Fh = T  132x44                                  mono
10h =   reserved
11h = G                1280x350  4               EGA only
12h = G                1280x600  4               EGA only
13h = G                640x350   256             EGA only
14h = G                640x400   256
15h = G                512x480   256
16h = T   80x30  8x16            256             VGA only
18h = T  100x27  8x16            16              VGA only
20h = G                1024x768  16              Everex 629,678
21h = T  160x64  8x16  1280x1024 16              1MB VGA only
30h = G                640x480   256             Everex 629,678
31h = G                800x600   256             Everex 629,678
32h = G  128x48  8x16  1024x768  256             1MB VGA only
40h = T  132x30  8x16            16              VGA only
50h = T  132x32  8x16            mono            VGA only
62h = G   40x25  8x8   320x200   32K             Vwpt TC (EV629)
70h = G   64x30  8x16  512x480   32K             Viewpoint TC
71h = G   80x30  8x16  640x480   32K             Viewpoint TC
76h = G   64x30  8x16  512x480   16M             Viewpoint TC
77h = G   80x30  8x16  640x480   16M             Viewpoint TC
----------107000BX0000-----------------------
INT 10 - Everex Extended Video BIOS - RETURN EMULATION STATUS
       AX = 7000h
       BX = 0000h
Return: CL = monitor type
            00h mono
            01h CGA
            02h EGA
            03h digital multifrequency
            04h IBM PS/2
            05h IBM 8514
            06h SuperVGA
            07h analog multifrequency
            08h super multifrequency
       CH = feature bits
            bits 7,6: 00 = 256K memory
                      01 = 512K memory
                      10 = 1024K
                      11 = 2048K memory
            bit 5:    special oscillator present
            bit 4:    VGA protect enabled
            bit 0:    6845 emulation
       DX = video board info
            bits 4-15: board ID model
            bits 0-3:  board ID revision
       DI = BCD BIOS version number
----------107000BX0004-----------------------
INT 10 - Everex Extended Video BIOS - GET PAGING FUNCTION POINTER FOR CURR MODE
       AX = 7000h
       BX = 0004h
Return: ES:DI -> FAR paging function (call with DL = page to set)
Note:   the word preceding ES:DI is the length of the function in bytes, and
       the last byte of the function is a FAR return instruction.
SeeAlso: AX=4F05h,AX=7000h/BX=0000h,AX=7000h/BX=0005h
----------107000BX0005-----------------------
INT 10 - Everex Extended Video BIOS - GET SUPPORTED MODE INFO
       AX = 7000h
       BX = 0005h
       CL = maximum number of modes to get info for
       CH = mode type to get info for (see below)
       DL = monitor type to get info for
       ES:DI -> buffer for mode info (see below)
Return: CL = total number of modes fitting criteria
       CH = size of each info record
SeeAlso: AX=7000h/BX=0000h,AX=7000h/BX=0004h

Values for mode type:
00h all modes
01h monochrome text modes
02h color text modes
03h four-color CGA graphics modes
04h two-color CGA graphics modes
05h 16-color graphics modes
06h 256-color graphics modes

Format of mode information record:
Offset Size  Description
00h   BYTE  mode number (bit 7 set if extended mode)
01h   BYTE  mode type (see above)
02h   BYTE  info bits
            bits 7,6 reserved
                   5 monochrome mode
                   4 interlaced display
                   3 requires special oscillator
                 2,1 memory required
                     00 = 256K
                     01 = 512K
                     10 = 1024K
                     11 = 2048K
                   0 reserved
03h   BYTE  font height
04h   BYTE  text columns on screen
05h   BYTE  text rows on screen
06h   WORD  number of scan lines
08h   BYTE  color information
            bits 7-4 reserved
                 3-0 bits per pixel